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| Tags: gravity, revisited, speed |
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#21
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On 9 mar, 19:49, Albertito wrote:
On 7 mar, 13:56, Eric Gisse wrote: On Mar 7, 2:16 am, Albertito wrote: On 6 mar, 23:02, Eric Gisse wrote: On Mar 6, 11:41 am, Albertito wrote: There are evidences showing that in Solar system, the speed of gravity is many orders of magnitude higher than the speed of light. No, there is not. Just because you say so doesn't mean it is true. But, what must we understand by speed of gravity?. Aetherists often claim that gravity are longitudinal waves, whereas light are transverse waves through the aether. Why even mention this? Ether has been ruled out as a viable concept EVERY SINGLE TIME for the last hundred and thirty years. Nobody but cranks in the fringe take ether seriously anymore. What is spacetime but a kind of ether? Spacetime in no way resembles ether. Learn what both the concepts represent. We know that in any medium longitudinal waves travel faster than transverse waves. Only if the medium is anisotropic. Where are the calculations in which you actually derive the things you write? Wrong. Anisotropy is not a requirement for the speed of longitudinal waves were higher than the speed of transverse ones. In isotropic and homogenous medium that difference in speed holds too. Show me the derivation. [snip spew] You are not listening. You write down a bunch of equations but you don't justify or derive any of them. Look at these equations, c_L^2 = (2G/d_0)(1-v)/(1-2v) c_S^2 = G/d_0 c_L is longitudinal speed c_S is transverse speed, d_0 is mass density, G is G is shear modulus, and v is Poison's ratio For an isotropic medium, the Poison's ratio is the same in any direction. Therefore, c_L = c_S only in the case v = 0. This case can only occurs for a medium which were perfectly compressible. So, it is clear that the factor (1-v)/(1-2v) can only be greater or equal to 1, yieding always c_L = c_S. Sorry, I made a mistake, I meant c_L = c_S can only occur in the case (1-v)/(1-2v) = 1/2. But, that case can't occur for any real value of v. |
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#22
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On Mar 9, 11:49 am, Albertito wrote:
On 7 mar, 13:56, Eric Gisse wrote: On Mar 7, 2:16 am, Albertito wrote: On 6 mar, 23:02, Eric Gisse wrote: On Mar 6, 11:41 am, Albertito wrote: There are evidences showing that in Solar system, the speed of gravity is many orders of magnitude higher than the speed of light. No, there is not. Just because you say so doesn't mean it is true. But, what must we understand by speed of gravity?. Aetherists often claim that gravity are longitudinal waves, whereas light are transverse waves through the aether. Why even mention this? Ether has been ruled out as a viable concept EVERY SINGLE TIME for the last hundred and thirty years. Nobody but cranks in the fringe take ether seriously anymore. What is spacetime but a kind of ether? Spacetime in no way resembles ether. Learn what both the concepts represent. We know that in any medium longitudinal waves travel faster than transverse waves. Only if the medium is anisotropic. Where are the calculations in which you actually derive the things you write? Wrong. Anisotropy is not a requirement for the speed of longitudinal waves were higher than the speed of transverse ones. In isotropic and homogenous medium that difference in speed holds too. Show me the derivation. [snip spew] You are not listening. You write down a bunch of equations but you don't justify or derive any of them. Look at these equations, c_L^2 = (2G/d_0)(1-v)/(1-2v) c_S^2 = G/d_0 You are, once again, missing the point. I want a derivation of these equations from first principles. c_L is longitudinal speed c_S is transverse speed, d_0 is mass density, G is G is shear modulus, and v is Poison's ratio For an isotropic medium, the Poison's ratio is the same in any direction. Therefore, c_L = c_S only in the case v = 0. This case can only occurs for a medium which were perfectly compressible. So, it is clear that the factor (1-v)/(1-2v) can only be greater or equal to 1, yieding always c_L = c_S. |
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#23
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On 9 mar, 20:16, Eric Gisse wrote:
On Mar 9, 11:49 am, Albertito wrote: On 7 mar, 13:56, Eric Gisse wrote: On Mar 7, 2:16 am, Albertito wrote: On 6 mar, 23:02, Eric Gisse wrote: On Mar 6, 11:41 am, Albertito wrote: There are evidences showing that in Solar system, the speed of gravity is many orders of magnitude higher than the speed of light. No, there is not. Just because you say so doesn't mean it is true. But, what must we understand by speed of gravity?. Aetherists often claim that gravity are longitudinal waves, whereas light are transverse waves through the aether. Why even mention this? Ether has been ruled out as a viable concept EVERY SINGLE TIME for the last hundred and thirty years. Nobody but cranks in the fringe take ether seriously anymore. What is spacetime but a kind of ether? Spacetime in no way resembles ether. Learn what both the concepts represent. We know that in any medium longitudinal waves travel faster than transverse waves. Only if the medium is anisotropic. Where are the calculations in which you actually derive the things you write? Wrong. Anisotropy is not a requirement for the speed of longitudinal waves were higher than the speed of transverse ones. In isotropic and homogenous medium that difference in speed holds too. Show me the derivation. [snip spew] You are not listening. You write down a bunch of equations but you don't justify or derive any of them. Look at these equations, c_L^2 = (2G/d_0)(1-v)/(1-2v) c_S^2 = G/d_0 You are, once again, missing the point. I want a derivation of these equations from first principles. c_L is longitudinal speed c_S is transverse speed, d_0 is mass density, G is G is shear modulus, and v is Poison's ratio For an isotropic medium, the Poison's ratio is the same in any direction. Therefore, c_L = c_S only in the case v = 0. This case can only occurs for a medium which were perfectly compressible. So, it is clear that the factor (1-v)/(1-2v) can only be greater or equal to 1, yieding always c_L = c_S. From first principles? You're asking too much! Even Einstein would be unable to derive the speed of light from first principles! You are kidding, aren't you? No, you do not want that. You only want harassing. Although in this thread I realize you are clueless, as usual. You are who is missing the point here. |
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#24
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On Mar 9, 12:05 pm, Albertito wrote:
On 9 mar, 20:16, Eric Gisse wrote: On Mar 9, 11:49 am, Albertito wrote: On 7 mar, 13:56, Eric Gisse wrote: On Mar 7, 2:16 am, Albertito wrote: On 6 mar, 23:02, Eric Gisse wrote: On Mar 6, 11:41 am, Albertito wrote: There are evidences showing that in Solar system, the speed of gravity is many orders of magnitude higher than the speed of light. No, there is not. Just because you say so doesn't mean it is true. But, what must we understand by speed of gravity?. Aetherists often claim that gravity are longitudinal waves, whereas light are transverse waves through the aether. Why even mention this? Ether has been ruled out as a viable concept EVERY SINGLE TIME for the last hundred and thirty years. Nobody but cranks in the fringe take ether seriously anymore. What is spacetime but a kind of ether? Spacetime in no way resembles ether. Learn what both the concepts represent. We know that in any medium longitudinal waves travel faster than transverse waves. Only if the medium is anisotropic. Where are the calculations in which you actually derive the things you write? Wrong. Anisotropy is not a requirement for the speed of longitudinal waves were higher than the speed of transverse ones. In isotropic and homogenous medium that difference in speed holds too. Show me the derivation. [snip spew] You are not listening. You write down a bunch of equations but you don't justify or derive any of them. Look at these equations, c_L^2 = (2G/d_0)(1-v)/(1-2v) c_S^2 = G/d_0 You are, once again, missing the point. I want a derivation of these equations from first principles. c_L is longitudinal speed c_S is transverse speed, d_0 is mass density, G is G is shear modulus, and v is Poison's ratio For an isotropic medium, the Poison's ratio is the same in any direction. Therefore, c_L = c_S only in the case v = 0. This case can only occurs for a medium which were perfectly compressible. So, it is clear that the factor (1-v)/(1-2v) can only be greater or equal to 1, yieding always c_L = c_S. From first principles? You're asking too much! Only if your skill set isn't up to the task, which it appears to be. What I ask of you would be one problem out of a larger classical mechanics problem set. You don't have to go through it all, just write down the important parts. Even Einstein would be unable to derive the speed of light from first principles! I'm asking you to derive or show references for your primary working equations because I believe they can not be simultaneously true in an isotropic medium, much less be a part of your larger agenda of disproving SR. Plus, Einstein would be able to do what you say he couldn't. Deriving the speed of propagation for a medium is a homework exercise in both classical E&M and mechanics. You are kidding, aren't you? No, you do not want that. You only want harassing. Although in this thread I realize you are clueless, as usual. You are who is missing the point here. I'm making some old Pentium 3 systems into cluster compute nodes. They can't PXE, so I have to boot off a CD and do it the slow way. I'm going to be here for a few hours while this churns, so I have nothing better to do. Your whole point is that - somehow, though you can't explain how - a medium which not only supports transverse and longitudinal waves manages to have speeds of propagation that are different despite being isotropic. Then somehow - I have no idea how you do - you make the assertion that this not only applies to the speed of gravity, which you haven't justified, but that it applies to the speed of light as well. Even if your assertions about speeds of propagation were true [they aren't], you have in no way substantiated the links you are making. Science isn't about increasingly bold assertions - no matter how absurd it looks to an outsider. |
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#25
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Supertroll Eric Gisse trolled:
Why? because http://www.albinoblacksheep.com/flash/youare "Yours is a statement of profound ignorance in all of its parts." --- Uncle Al to Tom Roberts. Feb 2008 Eric is http://www.helinium.nl/trolltech.gif -- Dono is concubine Lady Chacha http://en.wikipedia.org/wiki/Yodo-Dono |
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#26
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Tom Roberts" writes:
[Roberts]: In the model of GR, gravity does not propagate at all, but changes in gravity propagate with speed c. That is directly in contradiction to experiment and observations. Binary pulsars are an obvious example, as I demonstrated (without any dissent) in Reference B below. But even the simplest orbit computation program can show the same thing. If you use light-time-retarded positions of bodies to compute orbits, the computed orbits are open spirals, in contradiction to observations. But you've obviously never done the experiment yourself, or have used only propagation delays in the potential field, which are irrelevant for orbit computation. See Reference (C). There is no way known to any person on this planet to avoid the conclusion that gravitational force propagates c without invoking some kind of physical miracle, such as an effect without a cause or the creation of new momentum out of nothingness. Mathematical relativists don't seem bothered by such miracles. Meanwhile, real world physicists know they must not invoke miracles in their theories because that makes them non-falsifiable, and therefore unscientific. [See Reference E.] [Roberts]: The GR model agrees with all these "evidences", and indeed it accounts MUCH more accurately than the Newtonian model for measurements in the solar system (including the perihelia of Mercury and other planets, the Shapiro time delay, the bending of EM radiation by the sun, the operation of the GPS, the frame dragging measured by the LAGEOS satellites, etc.). True but irrelevant because GR is a field theory and describes only the field. The gravitational potential field causes all the effects on your list. But it does not cause ordinary orbital motion. Nor do the field equations describe ordinary orbital motion. To get that, one must take a gradient of the potential (or its equivalent) to get what you like to call an "approximation" theory. In simple, classical physics lingo, that process develops an expression for the 3-space (Euclidean) acceleration of bodies in coordinate time, which gives the orbital motion, which is then compared against astronomical observations made in Euclidean 3-space using proper time clocks. Try computing an orbit with GR just once in any system with at least two significant masses, and you will discover that you cannot do it without adopting near-infinite gravitational force propagation speed between bodies applying forces to one another. Then the dawn will come, and you will finally understand what the "speed of gravity" issue is about. [Roberts]: it is MUCH better to discuss models and their agreement with experiments than to discuss MODEL-DEPENDENT quantities like "speed of gravity". The "speed of gravity" is not a model-dependent concept except at the level of parts per 100 million, any more than "perihelion motion" is model-dependent. Its simple meaning is: When a source mass accelerates, the speed of gravity is the ratio of the distance of a target body to the time elapsed before the target body responds. And every known experiment measures that elapsed interval to be zero within experimental error, making the speed of gravity c and approximately infinite. Relativists like to redefine the concept to refer to the speed of changes in the gravitational potential field, which everyone agrees is c. But that refers to gravitational waves, and avoids the issue of the propagation speed of gravitational force for determining the ordinary orbital motion of two masses around a common center of mass. One must either give up the causal link to a source mass, or agree that the force propagates from the source mass to the target body faster than c. Tom Van Flandern does not understand the real issues, and uses egregious PUNs to promulgate his claims. In particular, what he calls "speed" is not what anybody else would call "speed". The experiments he cites do NOT measure speed (usual meaning), and their actual measurements are fully consistent with GR, in which nothing propagates faster than c. Quit making up nonsense. The published papers are in references (A), (B), (C), and (D) below. "Speed" has its unambiguous, classical meaning in all of them, as the editors, reviewers, and readers have all understood. Where are your publications on the subject? [Juan]: For calculations of orbits we have to use the actual positions of bodies and not the perceived locations. [Roberts]: True in Newtonian mechanics; irrelevant in GR. The comparison of theory with observations is not relevant? How absurd! You are disconnected from reality. References: ** (A) "Possible new properties of gravity", Astrophys.&SpaceSci. 244:249-261 (1996); http://metaresearch.org/cosmology/gr...sofgravity.asp ** (B) "The speed of gravity - What the experiments say", Phys.Lett.A 250:1-11 (1998); http://metaresearch.org/cosmology/speed_of_gravity.asp ** (C) "Reply to comments on 'The speed of gravity'", Phys.Lett.A 262:261-263 (1999). ** (D) "Experimental Repeal of the Speed Limit for Gravitational, Electrodynamic, and Quantum Field Interactions", T. Van Flandern and J.P. Vigier, Found.Phys. 32:1031-1068 (2002); preprint under title "The speed of gravity - Repeal of the speed limit" at http://metaresearch.org/cosmology/gr...peed_limit.asp ** (E) "Physics has its principles", in Gravitation, Electromagnetism and Cosmology, K. Rudnicki, ed., C. Roy Keys Inc., Montreal, 87-101 (2001); http://metaresearch.org/cosmology/Ph...Principles.asp Tom Van Flandern - Sequim, WA - see our web site on frontier astronomy research at http://metaresearch.org |
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#27
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On Apr 1, 10:17 am, "Tom Van Flandern" wrote:
Tom Roberts" writes: [Roberts]: In the model of GR, gravity does not propagate at all, but changes in gravity propagate with speed c. That is directly in contradiction to experiment and observations. Binary pulsars are an obvious example, as I demonstrated (without any dissent) in Reference B below. But even the simplest orbit computation program can show the same thing. If you use light-time-retarded positions of bodies to compute orbits, the computed orbits are open spirals, in contradiction to observations. But you've obviously never done the experiment yourself, or have used only propagation delays in the potential field, which are irrelevant for orbit computation. See Reference (C). There is no way known to any person on this planet to avoid the conclusion that gravitational force propagates c without invoking some kind of physical miracle, such as an effect without a cause or the creation of new momentum out of nothingness. Mathematical relativists don't seem bothered by such miracles. Meanwhile, real world physicists know they must not invoke miracles in their theories because that makes them non-falsifiable, and therefore unscientific. [See Reference E.] While Professor Roberts is struggling to understand how a binary system still have to account for gravitational field varying with time, Professor Carlip addressed your claim that the speed of gravity being several billion times the speed of light in the following article. I have seen no public refutation to his work. http://arxiv.org/abs/gr-qc/9909087 The aberration can also be simply explained by the good old Galilean transformation. Any apparent distance must be corrected by the Galilean transform. In this paper, Professor Carlip is suggesting the gravitational distance between the stars must be corrected by this aberration. In doing so, it will cause a first-order cancellation on the issue of the speed of gravity. The argument between you and him centers around if the aberration must be corrected. Do you have any fundamental argument to suggest that the aberration should not be corrected in this case? |
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#28
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Koobee Wublee wrote on Tue, 01 Apr 2008 15:51:36 -0700:
Professor Carlip addressed your claim that the speed of gravity being several billion times the speed of light in the following article. I have seen no public refutation to his work. http://arxiv.org/abs/gr-qc/9909087 As pointed several times in this newsgroup Carlip is wrong about interactions. Carlip paper received a formal reply by van Flandern on: Experimental Repeal of the Speed Limit for Gravitational, Electrodynamic, and Quantum Field Interactions. 2002: Found. Phys. 32, 1031. Van Flandern, T; Vigier, J.P. First part of Carlip paper is a 'review' about electromagnetism. Carlip mistaken claims about retarded electromagnetic interactions were corrected in a number of papers. See for instance, Necessity of simultaneous co-existence of instantaneous and retarded interactions in classical electrodynamics. 1999: Int. J. of Mod. Phys. A 14(24), 3789. Chubykalo, Andrew E; Vlaev, Stoyan J. Carlip mistakes about electromagnetic fields and nonrelativistic limit of interactions have been also corrected in other published works. In all papers, the conclusions are that electromagnetic interactions are not retarded by c. Actually i am finishing a draft on foundational issues of Chubykalo dualism, the work includes an extension of dualism to gravitational interactions. The conclusion is again that gravitational interactions are *not* retarded by c (as one would wait). Several mistakes of Carlip paper (section on gravitation) are highlighted. Of course, the model of retarded interactions of GR arises as a well defined limit but it is not a fundamental model of interactions but one of limited aplicability. -- http://canonicalscience.org/en/misce...guidelines.txt |
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#29
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"Juan R." GonzĂĄlez-Ălvarez wrote on Wed, 02 Apr 2008 12:35:26 +0200:
The conclusion is again that gravitational interactions are *not* retarded by c (as one would wait). Several mistakes of Carlip paper (section on gravitation) are highlighted. I mean that gravitational interactions are *not* retarded by c (as one would wait in basis to recent works proving that electromagnetic interactions are not retarded indeed). -- http://canonicalscience.org/en/misce...guidelines.txt |
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#30
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On Apr 2, 3:35 am, "Juan R." González-Álvarez wrote:
Koobee Wublee wrote on Tue, 01 Apr 2008 15:51:36 -0700: Professor Carlip addressed your claim that the speed of gravity being several billion times the speed of light in the following article. I have seen no public refutation to his work. http://arxiv.org/abs/gr-qc/9909087 As pointed several times in this newsgroup Carlip is wrong about interactions. Carlip paper received a formal reply by van Flandern on: Experimental Repeal of the Speed Limit for Gravitational, Electrodynamic, and Quantum Field Interactions. 2002: Found. Phys. 32, 1031. Van Flandern, T; Vigier, J.P. Yes, I found it in his website now. So, after Professor turned Dr. Van Flandern's claim of infinite speed of gravity on its head, Dr. Van Flandern reversed the favor by turning Professor Carlip's claim in aberration of gravity on its very own head. It looks like Professor Carlip has somehow ignored the speed of one star in his aberration consideration. Has Professor Carlip offered any graceful retreat from that mistake? |
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